A stacked plate-type heat exchanger is made up of plurality of heat exchanger plates that are stacked one on top of each other. The plurality of plates define a conduit for flow of a first fluid, which in one embodiment is, for example and without limitation, a engine oil when the heat exchanger is, for example, an engine oil cooler (EOC). Each of the plurality of plates has at least a pair of openings that are aligned in the plurality of plates, and which form part of the inlet and outlet manifolds of the heat exchanger. The inlet and outlet manifolds have an inlet and outlet, respectively, and permit flow of the first fluid from the inlet to pass through the conduits (provided by the plurality of plates) and exit from the outlet. Different types of stacked plate-type heat exchangers are known in the art.
Typically, the inlet and outlet receive a fitting to which a hose or other tubing can be attached. One method of attaching a fitting to the heat exchanger is shown in FIG. 1, which shows a cross-sectional view of a fitting, having a flange, which is brazed to the reinforcement plate. One of the challenges with such a fitting assembly is associated with proper alignment of the fitting with the apertures of the reinforcement and cover plates. Sliding or shifting of the fitting can occur and can result in an improperly aligned fitting. In addition, clad material needs to be present on both sides of the reinforcement plate for brazing to form the fitting assembly.
To address some of the disadvantages associated with the fitting assembly shown in FIG. 1, alternative fitting assemblies can be used, as shown in FIGS. 2 and 3.
In the fitting assembly shown in FIG. 2, the fitting is provided with a flange, similar to that shown in FIG. 1. However, the flange is not present at the end of the fitting, but rather is positioned, such that the flange rests on the reinforcement plate of the heat exchanger and a portion of the fitting extends below the reinforcement plate and the cover plate of the heat exchanger. This portion of the fitting that extends below the cover plate undergoes a swaging operation to form a lip to clamp the reinforcement plate and the cover plate between the flange and the lip, to affix the fitting to the heat exchanger and form the fitting assembly.
FIG. 3 shows another example of the fitting assembly that can be used for affixing the fitting to the heat exchanger. The difference between the fitting assembly in FIG. 2 and FIG. 3 is that the fitting shown in FIG. 3 has a preformed large bead. A tool is inserted from the bottom of the fitting to expand the fitting wall outwards to secure it to the reinforcement plate and cover plate. This process of expanding from the inside is called “staking”. A swaging operation can also be performed on the lower portion of the fitting to form the lip (similar to the fitting shown in FIG. 2) to affix the fitting to the reinforcement and cover plates.
In the fitting assemblies described above, clad material is provided between the reinforcement plate and the cover plate of the heat exchanger. In addition, clad material is also provided on the top surface of the reinforcement plate, and is therefore, present on both sides of the reinforcement plate. During brazing operation, the clad material, which functions as a filler material, helps to bond the reinforcement plate to the cover plate, for bonding the fitting to the heat exchanger and for filling any voids. As clad material can be expensive, there is a need in the art to reduce the use of such material. Therefore, there is also a need in the art for a heat exchanger assembly where the clad material is present on one side of the reinforcement plate, rather than on both sides.
Further to the above, one of the challenges that can be associated with the fitting assemblies described above is the proper alignment of the fitting with the heat exchanger. In addition, during coupling of the fitting to the heat exchanger, care should be taken to ensure that the fitting is properly positioned with the heat exchanger, such that it does not result in unnecessary angular movement of the fitting. Therefore, there is a need in the art for a fitting assembly that can help to ensure proper positioning of the fitting, or more preferably the fitting is a self-positioning fitting. Moreover, there is a need in the art for a fitting assembly that can help with avoiding the unnecessary angular movement of the fitting during the coupling procedure.